The conclave lasts until a new Pope is elected.
According to the rules for a conclave established by Pope John Paul II in 1996, the only form of election that may take place is the Scrutiny, or ballot.
That does not mean that there will only be one ballot. In a papal election, there must be a majority. The winner does not simply get one more vote than his nearest competitor.
Until Pope Benedict XVI’s Motu proprio of June 11, 2007, the rules for “majority” could change during the course of a conclave.
Under this new rule, a two-thirds majority is required for the election of a new pope, no matter how long it takes. If, after three days of voting, a new Pope is not elected, one day would be dedicated to prayer, after which “only the two names which in the previous rounds had the highest number of votes will be considered, and the provision of a two third majority of the Cardinals present and voting for a valid election will remain.” The Motu proprio also states that these two candidates cannot vote in subsequent ballots. These are the most recent rules for a conclave and therefore will be the ones observed for this conclave of 2013.
Previously, for the first three days of a conclave, a two-thirds majority was required for the election of a new pope. For example, if there are 99 voting Cardinals, the winner of the election must receive 66 or more votes. If the number of cardinals is not divisible by 3, the election is won by two thirds plus one vote.
If a new pope is not elected in a particular Scrutiny, a new balloting session began immediately. Two balloting sessions would be held in the morning, and two in the afternoon. There was only one balloting session on the first day of a conclave.
These rules changed if no new pope has been elected after three days. At that time, voting was suspended for a maximum of one day to give the Cardinals an opportunity for prayer, informal discussion, and instruction by the senior Cardinal in the Order of Deacons.
If another seven ballots produced no election, a second pause for prayer and discussion take place, including instruction by the senior Cardinal in the Order of Priests.
After a third set of seven ballots that had not produced an election, the senior Cardinal in the Order of Bishops instructed the Cardinals.
If, after seven more ballots, there was still no election of a new pope, the Cardinal electors were invited to discuss the manner of proceeding. There were two options:
- balloting continued, with the winner receiving an absolute majority (more than half) the vote
- balloting continued with only the top two candidates from the ballot immediately preceding this one, with the winner receiving an absolute majority (more than half) the vote
The decision between these two forms of balloting was decided by an absolute majority.